package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件的上传和下载
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;
    /**
     * 文件上传的方法
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件,所以需要转存到指定位置
        log.info("图片为:{}",file.toString());

        //获得原始文件名
        String originalFilename = file.getOriginalFilename();
        //获得原始文件名的后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用UUID重新生成文件名,防止文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix;
        //判断是否存在目录结构
        File dir =new File(basePath);
        if(!dir.exists()){
            //目录不存在,需要创建
            dir.mkdirs();
        }
        //转存到指定位置
        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        //输入流,通过输入类读取文件内容
        try {
            FileInputStream fileInputStream =new FileInputStream(new File(basePath + name));
            //输出流,通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();
            //响应的是什么图片
            response.setContentType("image/jpeg");
            byte[] b =new byte[1024];
            int len  =0;
            while ((len = fileInputStream.read(b))!=-1){
                outputStream.write(b,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        }
    }
}
